Acknowledgments

The work presented here is based on the work I conducted as a post-doctoral fellow at the Institute of Heat and Mass Transfer at RWTH Aachen University between April 2004 and December 2010.

I am especially indebted to Prof. Dr.-Ing. Reinhold Kneer (Chair of the Institute of Heat and Mass Transfer, RWTH Aachen University) for his professional and personal support and in particular for having constant confidence in my work.

I owe my gratitude to Dr. Joao Luis Toste de Azevedo for his willingness to act as assessor. Dr. Azevedo gave me the opportunity (after finishing my Ph.D. at the Technical University at Sofia) to work with several interesting research projects at the Instituto Superior Tecnico, Lisbon, and he contributed to the success of my work via his expertise in the field of coal combustion modelling. I will always remember the fruitful exchange of ideas and warm hospitality I experienced there. I am very grateful to Prof. Dr.-Ing. Roman Weber (Technical University Clausthal, Germany) and Dr. Kurose (Kyoto University, Japan) for agreeing to be reviewers and for their continued interest in this work.

I would like to thank to Prof. Ulrich Renz for giving me the opportunity to work at WSA, RWTH Aachen. My thanks also to Dr. Bernd Hillemacher for his professional and personal support during my stay in Aachen.

My special thanks to Dr. Malte Förster, who created the framework for my study and who gave me every support to ensure success in my work. In Dr. Förster I found a stimulating discussion partner on basic concepts of oxycoal combustion chemistry. He was always willing to listen to scientifically related difficulties and was always helpful in finding solutions when problems arose.

I would like to thank all my former colleagues and all those who were involved directly and indirectly in this work at the Institute of Heat and Mass Transfer. The experimental results reported in this study would not be possible without their support and their strong engagement in the oxycoal test facility.

The financial assistance from the German Federal Ministry of Economics and Technology (BMWi, fkz 0326890a), Ministry of Innovation, Science, Research and Technology of the State of NRW (miwft, fkz 22320601703), RWE Power AG, E.on AG, Siemens AG, Linde AG, Hitachi Power Europe GmbH, MAN Turbo AG, and WS-Wearmeprozesstechnik GmbH, under the project OXYCOAL-AC, is also acknowledged.

Finally, I want to express the biggest thanks to my wife Mariana for her patience as well as her unlimited understanding and support, without which such work would not have been possible.